ETHYL ETHER

OSHA comments from the January 19, 1989 Final Rule on Air Contaminants Project extracted from 54FR2332 et. seq. This rule was remanded by the U.S. Circuit Court of Appeals and the limits are not currently in force.

CAS: 60-29-7; Chemical Formula: C₂H₅OC₂H₅

OSHA’s previous limit for ethyl ether was a 400-ppm TWA. The Agency proposed the same time-weighted-average TWA limit, with the addition of a 15-minute STEL of 500 ppm. These limits are established in the final rule and are consistent with those recommended by the ACGIH. Ethyl ether is a colorless, volatile, mobile liquid with a distinct odor and a burning, sweet taste. It is extremely flammable and is a severe fire and explosion hazard when exposed to heat or flame.

Ethyl ether causes narcosis and general anesthesia. Concentrations of 3.6 to 6.5 volumes percent in air are anesthetic to humans; 7- to 10-percent concentrations cause respiratory arrest, and concentrations greater than 10 percent are fatal (ACGIH 1986/Ex. 1-3, p. 259). Repeated workplace exposures deliberately induced to produce the so-called “ether jag” have caused narcosis, exhaustion, headache, dizziness, sleepiness, excitation, and other psychic disturbances (Hake and Rowe 1963a/Ex. 1-1152). In women, albuminuria and polycythemia may result (Browning 1965a/Ex. 1-1017). Repeated exposure may cause skin desiccation; irritation of the mucous membranes and eyes occurs on contact with the liquid or after exposure to high concentrations of the vapor (Hake and Rowe 1963a/Ex. 1-1152). Nelson and co-workers (1943/Ex. 1-66) reported that workers began to experience nasal irritation at 200 ppm (Nelson, Enge, Ross et al. 1943/Ex. 1-66). Henderson and Haggard (1943c, as cited in ACGIH 1986/Ex. 1-3, p. 259) calculated that the amount of ether absorbed by a man of average height at a concentration of 400 ppm would not cause intoxication. Armor (1950, as cited in ACGIH 1986/Ex. 1-3, p. 259) observed that exposure effects occur only at levels of 500 ppm and above.

NIOSH (Ex. 8-47, Table N2; Tr. pp. 3-86 and 3-89) did not concur with OSHA’s proposed limits and noted that some individuals may experience sensory irritation upon exposure to these levels, as evidenced by the Nelson, Enge, Ross et al. (1943/Ex. 1-66) study. However, this finding was not supported by Armor (1950, as cited in ACGIH 1986/Ex. 1-3, p. 259). OSHA received no other comments on its proposed limits. The Agency concludes that both of these limits are necessary to protect exposed workers against the significant risk of narcosis and irritation potentially associated with excursions above the 8-hour TWA level, and OSHA is establishing PELs of 400 ppm as an 8-hour TWA and 500 ppm as a 15-minute STEL for ethyl ether in today’s rule. The Agency has determined that irritation and narcosis caused by excessive exposure to ethyl ether constitute material impairments of health and functional capacity.